1. Field of the Invention
The present invention relates generally to the field of exercise equipment. More specifically the present invention relates to an exercise machine for exercising the hamstrings, the machine having at least one movement resistance weight and a weight support surface positioned below the weight, a weight displacement pedal slidably mounted to an upright pedal guide shaft, a machine frame and a pulley rotatably mounted on a pulley axle secured relative to the machine frame at a position above the at least one lifting weight and also above the weight displacement pedal, a cable having a cable distal end secured to the weight and having a cable proximal end secured to the weight displacement pedal, the cable being of a length relative to the elevation of the pulley such that when the weight is resting on the weight support surface the pedal is elevated above its rest position. The pedal preferably includes a pedal brake biased with brake engagement biasing means which engages the pedal guide shaft when at rest and which releases the pedal guide shaft upon application of downward force to the pedal against the biasing of the brake engagement biasing means, so that when the pedal is released, the brake engages the pedal guide shaft and prevents the weight from falling.
2. Description of the Prior Art
There have long been weight machines for exercising various muscles of the human body. Many of these have included stacks of discrete and separable weight plates, any desired number of which can be lifted by means of levers or pulleys. A problem with these prior machines has been that none have been suited to exercising the hamstrings and the muscles to which the hamstrings connect. Another problem has been that a sudden release of the weight plates causes the plates to fall freely and crash into plates or a support structure below the stack, causing potential damage to the machine, to the gym floor, and to the user if the falling weight plates should cause a pedal or grip to fly into high impact contact with his or her body.
It is thus an object of the present invention to provide an exercise machine which is configured to permit full range exercise of the hamstrings.
It is another object of the present invention to provide such an exercise machine which includes weight stack brake means to prevent suddenly released raised weight plates from falling and crashing into a plate or structure below the raised plates, and the resulting sudden displacement of pedals and grip handles.
It is still another object of the present invention to provide such an exercise machine which is compact and readily transported.
It is finally an object of the present invention to provide such an exercise machine which is safe, reliable, simple in construction and relatively inexpensive to manufacture.
The present invention accomplishes the above-stated objectives, as well as others, as may be determined by a fair reading and interpretation of the entire specification.
An exercise machine is provided for exercising the hamstrings, including at least one weight; a weight support surface below the weight; an upright weight guide shaft laterally spaced apart from the weight; a weight displacement pedal slidably mounted to the pedal guide shaft; a machine frame; a generally horizontal pulley axle secured to the machine frame at a position higher than the weight and higher than the weight displacement pedal and laterally between the weight and the pedal guide shaft; a pulley mounted on the pulley axle so that the pulley is rotatable relative to the machine frame; a cable extending over and riding on the pulley and having a cable distal end secured to the weight and having a cable proximal end secured to the weight displacement pedal, the cable being of a length so that when the weight rests on the weight support surface the weight displacement pedal is elevated.
The exercise machine preferably additionally includes a pedal brake positioned adjacent to the pedal guide shaft and biased with a brake engagement biasing mechanism to engage the pedal guide shaft and including a brake disengagement mechanism operatively connected to the pedal which releases the pedal guide shaft upon application of downward force on the weight displacement pedal against the biasing of the brake engagement biasing mechanism. The machine frame preferably includes a parallelepipped structure having a generally horizontal rectangular base frame, a generally horizontal rectangular top frame spaced above the base frame and laterally spaced apart upright frame posts interconnecting the base frame and the top frame. The frame posts preferably include a first proximal frame post and a first distal frame post and a second proximal frame post and a second distal frame post. The exercise machine preferably additionally includes a first pulley mounting member interconnecting and secured to the first proximal frame post and the first distal frame post, and a second pulley mounting member interconnecting and secured to the second proximal frame post and the second distal frame post, where the pulley axle extends between and is secured relative to the first pulley mounting member and the second pulley mounting member and passes through the center of the pulley, the pulley being positioned between the first pulley mounting member and the second pulley mounting member.
The pedal guide shaft preferably extends between and is secured to the base frame and the top frame. The at least one movement resistance weight preferably includes a weight guide port and is slidably mounted on an upright weight guide shaft extending through the weight guide port, the weight guide shaft extending between and being secured to the base frame and the top frame. The at least one movement resistance weight preferably includes a stack of discrete and separable weight plates and an upright plate engaging rod connected the cable distal end and having a longitudinal series of weight key passing holes, the engaging rod extending through registering engaging rod ports in the weight plates, and a weight key fitted underneath a given number of the weight plates selected for lifting in a given workout and into a corresponding engaging rod port. The exercise machine preferably additionally includes a housing cover fitted over the machine frame upper end and around the pulley to protect a user from injurious contact with the pulley and the cable.
The exercise machine preferably additionally includes a substantially horizontal base plate resting on the ground beneath the pedal, and base plate legs secured to the base plate and extending upwardly, and leg brackets connecting the base plate legs to two opposing frame posts.
The exercise machine preferably still additionally includes first and second grip handles secured relative to and extending from the frame upper end, above the weight displacement pedal. The exercise machine preferably still additionally includes a first grip arm connected to the first grip handle and a second grip arm connected to the second grip handle, the first and second grip arms extending forwardly from the frame; first and second grip arm support structures including a structure for receiving and slidably passing the first and second grip arms respectively and including a structure for securing the first and second grip arms at any of various forward extensions.
Each grip arm preferably includes a longitudinally extending grip arm keyway and wherein each grip arm support structure includes a grip arm key which fits into the corresponding the grip arm keyway for preventing rotation of each grip arm about its longitudinal axis while permitting each grip arm to slide longitudinally within the corresponding grip arm support structure.
The weight displacement pedal preferably includes a tubular pedal support arm formed of telescoping proximal and distal pedal support arm segments, where the weight displacement pedal is secured to the proximal pedal support arm segment and the cable proximal end is secured to the distal pedal support arm segment, the pedal distal support arm segment including a pedal guide tube slidably fitting around the pedal guide shaft, and including a mechanism for releasibly securing the proximal pedal support arm segment relative to the distal pedal support arm segment.